1. Field of the Invention
The present invention relates to a data processor, a program updating method and a storage medium, and more specifically a data processor, a program updating method and a storage medium which update a program with data sent from outside.
2. Related Background Art
In a data processor which executes various kinds of application programs such as those for personal data management functions, it is general to write a program such as firmware for obtaining executing environments for the application programs into a nonvolatile memory.
The program written in the nonvolatile memory is rewritten when a bug exists in the program or when a version of the program is to be upgraded.
Japanese Patent Application Laid-Open No. 6-44064 discloses a method to rewrite the program stored in the nonvolatile memory. This method is configured by receiving and temporarily holding an updating program sent from outside by way of a broadcast wave or a telephone network, and automatically rewriting the program stored in the nonvolatile memory into the received program.
Furthermore, digital broadcast has a high possibility to provide new kinds of services one after another as compared with conventional analog broadcast. Accordingly, a receiver for the digital broadcast which is newly purchased may soon be out-of-date when its functions remain unchanged from those at the time of purchase and cannot cope with new kinds of services.
In order to solve such problem, there is a concept of modifying a software program to cope with new kinds of services without changing any hardware of the receiver. That is, there is a method which sends a program in a condition overlapped with a broadcast wave for downloading, thereby updating a program in an instrument which is capable of receiving the digital broadcast.
However, the method disclosed by Japanese Patent Application Laid-Open No. 6-44064 is configured by rewriting the program stored in the nonvolatile memory into a new program and may update the program incompletely when a power supply is intercepted due to power failure during the updating of the program, thereby resulting in a situation where a system cannot start up due to the incomplete updating of the program.
Furthermore, the method does not take an operating condition of the instrument into consideration for downloading and may update the program even while the receiving instrument is operating, thereby resulting in an erroneous operation of the instrument.